ABSTRACT
OBJECTIVE: To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons. METHODS: Gestational-age- and chorionicity-specific reference distributions for singleton percentiles and EFW were fitted to data on 4391 twin pregnancies with two liveborn fetuses from four European centers, including 3323 dichorionic (DC) and 1068 monochorionic diamniotic (MCDA) twin pregnancies. Gestational age was derived using the larger of the two crown-rump length measurements obtained during the first trimester of pregnancy. EFW was obtained from ultrasound measurements of head circumference, abdominal circumference and femur length using the Hadlock formula. Singleton percentiles were obtained using the Fetal Medicine Foundation population weight charts for singleton pregnancies. Hierarchical models were fitted to singleton Z-scores with autoregressive terms for serial correlations within the same fetus and between twins from the same pregnancy. Separate models were fitted for DC and MCDA twins. RESULTS: Fetuses from twin pregnancies tended to be smaller than singletons at the earliest gestational ages (16 weeks for MCDA and 20 weeks for DC twins). This was followed by a period of catch-up growth until around 24 weeks. After that, both DC and MCDA twins showed reduced growth. In DC twins, the EFW corresponding to the 50th percentile was at the 50th percentile of singleton pregnancies at 23 weeks, the 43rd percentile at 28 weeks, the 32nd percentile at 32 weeks and the 22nd percentile at 36 weeks. In MCDA twins, the EFW corresponding to the 50th percentile was at the 36th percentile of singleton pregnancies at 24 weeks, the 29th percentile at 28 weeks, the 19th percentile at 32 weeks and the 12th percentile at 36 weeks. CONCLUSIONS: In DC and, to a greater extent, MCDA twin pregnancies, fetal growth is reduced compared with that observed in singleton pregnancies. Furthermore, after 24 weeks, the divergence in growth trajectories between twin and singleton pregnancies becomes more pronounced as gestational age increases. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Fetal Development , Perinatology , Pregnancy , Female , Humans , Pregnancy, Twin , Gestational Age , Fetal Weight , Twins, Dizygotic , Retrospective Studies , Ultrasonography, Prenatal , Fetal Growth Retardation/diagnostic imaging , Fetal Growth Retardation/epidemiologySubject(s)
Biomarkers , Placenta Growth Factor , Pre-Eclampsia , Humans , Female , Pregnancy , Pre-Eclampsia/blood , Pre-Eclampsia/diagnosis , Placenta Growth Factor/blood , Biomarkers/blood , AdultABSTRACT
OBJECTIVE: To compare the performance at 35 + 0 to 36 + 6 weeks' gestation of screening for delivery with pre-eclampsia (PE) at various timepoints, using one of three approaches: placental growth factor (PlGF) concentration, soluble fms-like tyrosine kinase-1 (sFlt-1) to PlGF concentration ratio, or the competing-risks model, which combines maternal risk factors with biomarkers to estimate patient-specific risk. METHODS: This was a prospective observational study of women attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation at one of two maternity hospitals in England between 2016 and 2022. During the visit, maternal demographic characteristics and medical history were recorded and serum PlGF, serum sFlt-1 and mean arterial pressure (MAP) were measured. Detection rates (DRs) were evaluated for delivery with PE (defined as per American College of Obstetricians and Gynecologists 2019 criteria) within 1 week, within 2 weeks or at any time after screening, using the following strategies: (i) low PlGF (< 10th percentile); (ii) high sFlt-1/PlGF ratio (> 90th percentile); or (iii) the competing-risks model, in which maternal factors were combined with multiples of the median values of PlGF ('single test'), PlGF and sFlt-1 ('double test') or PlGF, sFlt-1 and MAP ('triple test'). Risk cut-offs corresponded to a screen-positive rate of 10%. DRs were compared between tests. RESULTS: Of 34 782 pregnancies, 831 (2.4%) developed PE. In screening for delivery with PE at any time from assessment, the DR at 10% screen-positive rate was 47% by low PlGF alone, 54% by the single test, 55% by high sFlt-1/PlGF ratio, 61% by the double test and 68% by the triple test. In screening for delivery with PE within 2 weeks from assessment, the respective values were 67%, 74%, 74%, 80% and 87%. In screening for delivery with PE within 1 week from assessment, the respective values were 77%, 81%, 85%, 88% and 91%. For prediction of PE at any time, the DR was significantly higher with the triple test compared to PlGF alone or the sFlt-1/PlGF ratio, with a DR difference (95% CI) of 20.1% (16.7-23.0%) and 12.4% (9.7-15.3%), respectively. Similar results were seen for prediction of PE within 2 weeks (20.6% (14.9-26.8%) and 12.9% (7.7-17.5%), respectively) and prediction of PE within 1 week (13.5% (5.4-21.6%) and 5.4% (0.0-10.8%), respectively). The double test was superior to the sFlt-1/PlGF ratio and the single test was superior to PlGF alone in the prediction of PE within 2 weeks and at any time from assessment, but not within 1 week of assessment. CONCLUSION: At 35 + 0 to 36 + 6 weeks' gestation, the performance of screening for PE by the competing-risks model triple test is superior to that of PlGF alone or the sFlt-1/PlGF ratio for the development of disease within 1 week, within 2 weeks and at any time from screening. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Hypertension, Pregnancy-Induced , Pre-Eclampsia , Pregnancy , Female , Humans , Pregnancy Trimester, Third , Placenta Growth Factor , Vascular Endothelial Growth Factor Receptor-1 , Vascular Endothelial Growth Factor A , Gestational Age , Biomarkers , Predictive Value of TestsABSTRACT
OBJECTIVES: To examine the relationship between the English index of multiple deprivation (IMD) and the incidence of pre-eclampsia (PE), evaluate the distribution of IMD in a cohort of ethnically diverse pregnant women in South East England and assess whether IMD improves the prediction of PE compared with that provided by the 'history-only' competing-risks model (based on maternal characteristics and medical history). METHODS: This was a prospective, observational study of 159 125 women with a singleton pregnancy who attended their first routine hospital visit at 11 + 0 to 13 + 6 weeks' gestation in two maternity hospitals in the UK. The inclusion criteria were delivery at ≥ 24 weeks' gestation of babies without major abnormality. Participants completed a questionnaire on demographic characteristics and obstetric and medical history, which was then reviewed by a doctor together with the woman. Patients were asked to self-identify as white, black, South Asian, East Asian or mixed race. IMD was used as a measure of socioeconomic status, which takes into account income, employment, education, skills and training, health and disability, crime, barriers to housing and services, and living environment. Each neighborhood is ranked according to their level of deprivation relative to that of other areas into one of five equal groups, with Quintile 1 containing the 20% most deprived areas and Quintile 5 containing the 20% least deprived areas. IMD was assigned based on a woman's postcode. Risk factors for PE and its incidence were assessed across IMD using chi-square test or t-test, as appropriate. The relationship between IMD and gestational age at delivery with PE was evaluated by fitting parametric survival models for IMD alone, IMD combined with race and IMD combined with the Fetal Medicine Foundation history-only competing-risks model. RESULTS: The incidence of PE (n = 4088, 2.6%) increased progressively across IMD quintiles, from 2.0% in Quintile 5 (least deprived) to 3.0% in Quintile 1 (most deprived). Compared with white women and those in other racial groups, black women had a higher incidence of PE (4.8%), were less often in IMD Quintiles 4 and 5, and were more often in IMD Quintiles 1 and 2. None of the IMD quintiles improved the prediction of PE compared with that provided by the history-only competing-risks model (which includes race). The history-only competing-risks model with vs without IMD had a similar detection rate for delivery with PE at < 37 weeks' gestation (44.1% (95% CI, 41.1-47.2%) vs 43.9% (95% CI, 40.1-47.0%)) and at any gestational age (35.2% (95% CI, 33.8-36.7%) vs 35.1% (95% CI, 33.7-36.6%)), at a 10% screen-positive rate. CONCLUSIONS: The incidence of PE is higher in women living in the most deprived areas in South East England and in black women (vs those of other racial groups), who also live in areas of higher deprivation. However, in screening for PE, inclusion of IMD does not improve the prediction of PE provided by race and other maternal characteristics and elements of medical history. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Pre-Eclampsia , Pregnancy , Female , Humans , Pre-Eclampsia/diagnosis , Risk Assessment , Incidence , Prospective Studies , Risk Factors , Gestational Age , Biomarkers , Placenta Growth FactorABSTRACT
OBJECTIVES: To examine the relationship between the English index of multiple deprivation (IMD) and the incidence of stillbirth and assess whether IMD contributes to the prediction of stillbirth provided by the combination of maternal demographic characteristics and elements of medical history. METHODS: This was a prospective, observational study of 159 125 women with a singleton pregnancy who attended their first routine hospital visit at 11 + 0 to 13 + 6 weeks' gestation in two maternity hospitals in the UK. The inclusion criterion was delivery at ≥ 24 weeks' gestation of a fetus without major abnormality. Participants completed a questionnaire on demographic characteristics and obstetric and medical history. IMD was used as a measure of socioeconomic status, which takes into account income, employment, education, skills and training, health and disability, crime, barriers to housing and services, and living environment. Each neighborhood is ranked according to its level of deprivation relative to that of other areas into one of five equal groups, with Quintile 1 containing the 20% most deprived areas and Quintile 5 containing the 20% least deprived areas. Logistic regression analysis was used to determine whether IMD provided a significant independent contribution to stillbirth after adjustment for known maternal risk factors. RESULTS: The overall incidence of stillbirth was 0.35% (551/159 125), and this was significantly higher in the most deprived compared with the least deprived group (Quintile 1 vs Quintile 5). The odds ratio (OR) in Quintile 1 was 1.57 (95% CI, 1.16-2.14) for any stillbirth, 1.64 (95% CI, 1.20-2.28) for antenatal stillbirth and 1.89 (95% CI, 1.23-2.98) for placental dysfunction-related stillbirth. In Quintile 1 (vs Quintile 5), there was a higher incidence of factors that contribute to stillbirth, including black race, increased body mass index, smoking, chronic hypertension and previous stillbirth. The OR of black (vs white) race was 2.58 (95% CI, 2.14-3.10) for any stillbirth, 2.62 (95% CI, 2.16-3.17) for antenatal stillbirth and 3.34 (95% CI, 2.59-4.28) for placental dysfunction-related stillbirth. Multivariate analysis showed that IMD did not have a significant contribution to the prediction of stillbirth provided by maternal race and other maternal risk factors. In contrast, in black (vs white) women, the risk of any and antenatal stillbirth was 2.4-fold higher and the risk of placental dysfunction-related stillbirth was 2.9-fold higher after adjustment for other maternal risk factors. CONCLUSIONS: The incidence of stillbirth, particularly placental dysfunction-related stillbirth, is higher in women living in the most deprived areas in South East England. However, in screening for stillbirth, inclusion of IMD does not improve the prediction provided by race, other maternal characteristics and elements of medical history. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Placenta Diseases , Stillbirth , Female , Pregnancy , Humans , Infant, Newborn , Stillbirth/epidemiology , Incidence , Prospective Studies , Placenta , Infant, Small for Gestational Age , Risk FactorsABSTRACT
OBJECTIVES: To develop further a competing-risks model for the prediction of a small-for-gestational-age (SGA) neonate by including sonographically estimated fetal weight (EFW) and biomarkers of impaired placentation at 36 weeks' gestation, and to compare the performance of the new model with that of the traditional EFW < 10th percentile cut-off. METHODS: This was a prospective observational study in 29 035 women with a singleton pregnancy undergoing routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation. A competing-risks model for the prediction of a SGA neonate was used. The parameters included in the prior-history model were provided in previous studies. An interaction continuous model was used for the EFW likelihood. A folded plane regression model was fitted to describe likelihoods of biomarkers of impaired placentation. Stratification plans were also developed. The new model was evaluated and compared with EFW percentile cut-offs. RESULTS: The performance of the model was better for predicting SGA neonates delivered closer to the point of assessment. The prediction provided by maternal factors alone was improved significantly by the addition of EFW, uterine artery pulsatility index (UtA-PI) and placental growth factor (PlGF) but not by mean arterial pressure or soluble fms-like tyrosine kinase-1. At a 10% false-positive rate, maternal factors and EFW predicted 77.6% and 65.8% of SGA neonates < 10th percentile delivered before 38 and 42 weeks, respectively. The respective figures for SGA < 3rd percentile were 85.5% and 74.2%. Addition of UtA-PI and PlGF resulted in marginal improvement in prediction of SGA < 3rd percentile requiring imminent delivery. A competing-risks approach that combines maternal factors and EFW performed better when compared with fixed EFW percentile cut-offs at predicting a SGA neonate, especially with increasing time interval between assessment and delivery. The new model was well-calibrated. CONCLUSIONS: A competing-risks model provides effective risk stratification for a SGA neonate at 35 + 0 to 36 + 6 weeks' gestation and is superior to EFW percentile cut-offs. The use of biomarkers of impaired placentation in addition to maternal factors and fetal biometry results in small improvement of the predictive performance for a neonate with severe SGA. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Fetal Weight , Ultrasonography, Prenatal , Pregnancy , Infant, Newborn , Female , Humans , Infant , Placenta Growth Factor , Pregnancy Trimester, Third , Ultrasonography, Prenatal/methods , Predictive Value of Tests , Gestational Age , Fetal Growth Retardation , BiomarkersABSTRACT
OBJECTIVE: The competing-risks model for assessment of risk for pre-eclampsia (PE) at 35-37 weeks' gestation identifies the majority of women who are at high risk of subsequent delivery with PE. We aimed to examine the incidence and relative risk of adverse pregnancy outcomes in patient groups stratified according to the estimated risk of delivery with PE. METHODS: This was a prospective non-interventional, observational study in women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. The risk of delivery with PE for each patient in the study population was estimated using the competing-risks model, combining the prior distribution of gestational age at delivery with PE and the likelihood from multiples of the median values of mean arterial pressure, placental growth factor and soluble fms-like tyrosine kinase-1. The patients were assigned to one of the following five risk categories: Group A, ≥ 1 in 2; Group B, 1 in 5 to 1 in 3; Group C, 1 in 20 to 1 in 6; Group D, 1 in 50 to 1 in 21; and Group E, < 1 in 50. The outcome measures were delivery with PE, gestational hypertension (GH), small-for-gestational age (SGA) at birth, delivery by Cesarean section, stillbirth, neonatal death, perinatal death and admission to the neonatal unit (NNU) for at least 48 h. In each risk category, the proportion of women with each adverse outcome was determined and relative risks (RR) were calculated as compared with the lowest-risk Group E. RESULTS: In the study population of 29 035 women, 1.6%, 2.7%, 8.2%, 9.8% and 77.8% were categorized into Groups A, B, C, D and E, respectively. Compared with women in Group E, women in the higher-risk groups were more likely to have an adverse outcome. The RR of delivery with PE in Group A compared with Group E was 65.5 (95% CI, 54.1-79.1) and the respective values were 11.9 (95% CI, 9.1-15.5) for GH, 1.8 (95% CI, 1.5-2.1) for delivery by emergency Cesarean section, 1.5 (95% CI, 1.2-1.8) for delivery by elective Cesarean section, 8.9 (95% CI, 7.4-10.8) for SGA with birth weight < 3rd percentile, 4.8 (95% CI, 4.3-5.4) for SGA with birth weight < 10th percentile, 5.3 (95% CI, 1.4-20.5) for stillbirth and 3.4 (95% CI, 2.8-4.2) for NNU admission for ≥ 48 h. The RR for these pregnancy complications in higher-risk groups (vs Group E) was particularly high for cases with delivery within 2 weeks after assessment. In terms of SGA, both for birth weight < 10th and < 3rd percentiles, the trend in all cases was stronger than that observed when the analysis was confined to normotensive pregnancies. The rates of neonatal death were too small to allow meaningful comparisons between risk groups. CONCLUSION: Pregnant women identified by the competing-risks model to be at high risk of PE are also at increased risk of GH, Cesarean section, stillbirth, SGA and NNU admission for ≥ 48 h. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Perinatal Death , Pre-Eclampsia , Birth Weight , Cesarean Section , Female , Fetal Growth Retardation , Gestational Age , Humans , Infant, Newborn , Perinatal Death/etiology , Placenta Growth Factor , Pre-Eclampsia/epidemiology , Pregnancy , Pregnancy Outcome/epidemiology , Pregnancy Trimester, Third , Prospective Studies , Stillbirth/epidemiology , Ultrasonography, Prenatal , Uterine Artery/diagnostic imagingABSTRACT
OBJECTIVE: To examine the distribution of birth weight according to gestational age in pregnancies complicated by pre-eclampsia (PE) and assess the potential value of sonographic estimated fetal weight (EFW) at mid-gestation as a predictor of PE. METHODS: The data for this study were derived from prospective screening for adverse obstetric outcome in 93 911 women with a singleton pregnancy attending for routine pregnancy care at 19 + 0 to 24 + 6 weeks' gestation in two UK maternity hospitals. This visit included recording of maternal demographic characteristics and medical history, sonographic EFW and measurement of mean arterial pressure (MAP) and uterine artery pulsatility index (UtA-PI). The distribution of birth weight of pregnancies with and those without PE was assessed. The competing-risks model was used to estimate the individual, patient-specific risk of delivery with PE at < 32 and < 37 weeks' gestation and at any gestational age. The areas under the receiver-operating-characteristics curves and detection rates (DRs) of delivery with PE, at a 10% false-positive rate (FPR), were assessed for various combinations of maternal risk factors, EFW, MAP and UtA-PI. McNemar's test was used to determine the significance of difference in DR at a 10% FPR between screening with vs without EFW. RESULTS: The study population contained 2843 (3.0%) pregnancies that subsequently developed PE, including 148 (0.2%) that delivered with PE at < 32 weeks' gestation and 654 (0.7%) that delivered with PE at < 37 weeks. Birth weight was < 10th percentile in 82% of pregnancies with PE delivering at < 32 weeks' gestation and this decreased to 21% of those with PE delivering at ≥ 37 weeks. In screening for delivery with PE at < 32 and < 37 weeks' gestation, the DR, at a 10% FPR, achieved by maternal risk factors (51% and 46%, respectively) was improved by addition of EFW (69% and 51%, respectively). Similarly, addition of EFW improved the performance of screening by a combination of maternal risk factors and MAP from 72% to 80% for PE < 32 weeks and from 57% to 60% for PE < 37 weeks. EFW did not improve the predictive performance of screening by a combination of maternal risk factors, MAP and UtA-PI. CONCLUSIONS: In pregnancies complicated by preterm PE, a high proportion of neonates are small-for-gestational age, and sonographic EFW at mid-gestation can improve the prediction of early and preterm PE provided by maternal risk factors and MAP but not the prediction provided by a combination of maternal risk factors, MAP and UtA-PI. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Fetal Weight , Pre-Eclampsia , Biomarkers , Birth Weight , Female , Gestational Age , Humans , Infant, Newborn , Placenta Growth Factor , Pre-Eclampsia/diagnostic imaging , Predictive Value of Tests , Pregnancy , Prospective Studies , Pulsatile Flow , Ultrasonography, Prenatal , Uterine Artery/diagnostic imagingABSTRACT
OBJECTIVE: To estimate the risk of fetal loss associated with chorionic villus sampling (CVS) in twin pregnancy, using propensity score analysis. METHODS: This was a multicenter cohort study of women with twin pregnancy undergoing ultrasound examination at 11-13 weeks' gestation, performed in eight fetal medicine units in which the leadership were trained at the Harris Birthright Research Centre for Fetal Medicine in London, UK, and in which the protocols for screening, invasive testing and pregnancy management are similar. The risk of death of at least one fetus was compared between pregnancies that had and those that did not have CVS, after propensity score matching (1:1 ratio). This procedure created two comparable groups by balancing the maternal and pregnancy characteristics that lead to CVS being performed, similar to how randomization operates in a randomized clinical trial. RESULTS: The study population of 8581 twin pregnancies included 445 that had CVS. Death of one or two fetuses at any stage during pregnancy occurred in 11.5% (51/445) of pregnancies in the CVS group and in 6.3% (515/8136) in the non-CVS group (P < 0.001). The propensity score algorithm matched 258 cases that had CVS with 258 non-CVS cases; there was at least one fetal loss in 29 (11.2%) cases in the CVS group and in 35 (13.6%) cases in the matched non-CVS group (odds ratio (OR), 0.81; 95% CI, 0.48-1.35; P = 0.415). However, there was a significant interaction between the risk of fetal loss after CVS and the background risk of fetal loss; when the background risk was higher, the risk of fetal loss after CVS decreased (OR, 0.46; 95% CI, 0.23-0.90), while, in pregnancies with a lower background risk of fetal loss, the risk of fetal loss after CVS increased (OR, 2.45; 95% CI, 0.95-7.13). The effects were statistically significantly different (P-value of the interaction = 0.005). For a pregnancy in which the background risk of fetal loss was about 6% (the same as in our non-CVS population), there was no change in the risk of fetal loss after CVS, but, when the background risk was more than 6%, the posterior risk was paradoxically reduced, and when the background risk was less than 6%, the posterior risk increased exponentially; for example, if the background risk of fetal loss was 2.0%, the relative risk was 2.8 and the posterior risk was 5.6%. CONCLUSION: In twin pregnancy, after accounting for the risk factors that lead to both CVS and spontaneous fetal loss and confining the analysis to pregnancies at lower prior risk, CVS seems to increase the risk of fetal loss by about 3.5% above the patient's background risk. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Amniocentesis/adverse effects , Chorionic Villi Sampling/adverse effects , Pregnancy, Twin , Prenatal Diagnosis/adverse effects , Congenital Abnormalities/diagnosis , Female , Humans , Pregnancy , Pregnancy Trimester, First , Propensity Score , Ultrasonography, PrenatalABSTRACT
OBJECTIVE: To examine the predictive performance of a previously reported competing-risks model of screening for pre-eclampsia (PE) at 35-37 weeks' gestation by combinations of maternal risk factors, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum soluble fms-like tyrosine kinase-1 (sFlt-1) in a validation dataset derived from the screened population of the STATIN study. METHODS: This was a prospective third-trimester multicenter study of screening for PE in singleton pregnancies by means of a previously reported algorithm that combines maternal risk factors and biomarkers. Women in the high-risk group were invited to participate in a trial of pravastatin vs placebo, but the trial showed no evidence of an effect of pravastatin in the prevention of PE. Patient-specific risks of delivery with PE were calculated using the competing-risks model, and the performance of screening for PE by maternal risk factors alone and by various combinations of risk factors with MAP, UtA-PI, PlGF and sFlt-1 was assessed. The predictive performance of the model was examined by, first, the ability of the model to discriminate between the PE and no-PE groups using the area under the receiver-operating-characteristics curve (AUC) and the detection rate at a fixed false-positive rate of 10%, and, second, calibration by measurements of calibration slope and calibration-in-the-large. RESULTS: The study population of 29 677 pregnancies contained 653 that developed PE. In screening for PE by a combination of maternal risk factors, MAP, PlGF and sFlt-1 (triple test), the detection rate at a 10% false-positive rate was 79% (95% CI, 76-82%) and the results were consistent with the data used for developing the algorithm. Addition of UtA-PI did not improve the prediction provided by the triple test. The AUC for the triple test was 0.923 (95% CI, 0.913-0.932), demonstrating very high discrimination between affected and unaffected pregnancies. Similarly, the calibration slope was 0.875 (95% CI, 0.831-0.919), demonstrating good agreement between the predicted risk and observed incidence of PE. CONCLUSION: The competing-risks model provides an effective and reproducible method for third-trimester prediction of term PE. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Pre-Eclampsia/diagnosis , Pregnancy Trimester, Third , Prenatal Diagnosis/methods , Risk Assessment/methods , Adult , Arterial Pressure , Biomarkers/analysis , Calibration , False Positive Reactions , Female , Gestational Age , Humans , Placenta Growth Factor/blood , Pre-Eclampsia/prevention & control , Predictive Value of Tests , Pregnancy , Prospective Studies , Pulsatile Flow , ROC Curve , Randomized Controlled Trials as Topic , Reproducibility of Results , Uterine Artery/diagnostic imaging , Uterine Artery/physiopathology , Vascular Endothelial Growth Factor Receptor-1/bloodABSTRACT
OBJECTIVE: To examine the performance of a model combining maternal risk factors, uterine artery pulsatility index (UtA-PI) and estimated fetal weight (EFW) at 19-24 weeks' gestation, for predicting all antepartum stillbirths and those due to impaired placentation, in a training dataset used for development of the model and in a validation dataset. METHODS: The data for this study were derived from prospective screening for adverse obstetric outcome in women with singleton pregnancy attending for routine pregnancy care at 19 + 0 to 24 + 6 weeks' gestation. The study population was divided into a training dataset used to develop prediction models for placental dysfunction-related antepartum stillbirth and a validation dataset to which the models were then applied. Multivariable logistic regression analysis was used to develop a model based on a combination of maternal risk factors, EFW Z-score and UtA-PI multiples of the normal median. We examined the predictive performance of the model by, first, the ability of the model to discriminate between the stillbirth and live-birth groups, using the area under the receiver-operating-characteristics curve (AUC) and the detection rate (DR) at a fixed false-positive rate (FPR) of 10%, and, second, calibration by measurements of calibration slope and intercept. RESULTS: The study population of 131 514 pregnancies included 131 037 live births and 477 (0.36%) stillbirths. There are four main findings of this study. First, 92.5% (441/477) of stillbirths were antepartum and 7.5% (36/477) were intrapartum, and 59.2% (261/441) of antepartum stillbirths were observed in association with placental dysfunction and 40.8% (180/441) were unexplained or due to other causes. Second, placental dysfunction accounted for 80.1% (161/201) of antepartum stillbirths at < 32 weeks' gestation, 54.2% (52/96) at 32 + 0 to 36 + 6 weeks and 33.3% (48/144) at ≥ 37 weeks. Third, the risk of placental dysfunction-related antepartum stillbirth increased with increasing maternal weight and decreasing maternal height, was 3-fold higher in black than in white women, was 5.5-fold higher in parous women with previous stillbirth than in those with previous live birth, and was increased in smokers, in women with chronic hypertension and in parous women with a previous pregnancy complicated by pre-eclampsia and/or birth of a small-for-gestational-age baby. Fourth, in screening for placental dysfunction-related antepartum stillbirth by a combination of maternal risk factors, EFW and UtA-PI in the validation dataset, the DR at a 10% FPR was 62.3% (95% CI, 57.2-67.4%) and the AUC was 0.838 (95% CI, 0.799-0.878); these results were consistent with those in the dataset used for developing the algorithm and demonstrate high discrimination between affected and unaffected pregnancies. Similarly, the calibration slope was 1.029 and the intercept was -0.009, demonstrating good agreement between the predicted risk and observed incidence of placental dysfunction-related antepartum stillbirth. The performance of screening was better for placental dysfunction-related antepartum stillbirth at < 37 weeks' gestation compared to at term (DR at a 10% FPR, 69.8% vs 29.2%). CONCLUSIONS: Screening at mid-gestation by a combination of maternal risk factors, EFW and UtA-PI can predict a high proportion of placental dysfunction-related stillbirths and, in particular, those that occur preterm. Such screening provides poor prediction of unexplained stillbirth or stillbirth due to other causes. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Fetal Weight , Placenta Diseases/diagnosis , Prenatal Diagnosis/statistics & numerical data , Risk Assessment/statistics & numerical data , Stillbirth/epidemiology , Adult , Female , Gestational Age , Humans , Placenta/diagnostic imaging , Placentation , Predictive Value of Tests , Pregnancy , Pregnancy Trimester, Second , Prenatal Diagnosis/methods , Prospective Studies , Pulsatile Flow , Risk Assessment/methods , Ultrasonography, Doppler , Ultrasonography, Prenatal , Uterine Artery/diagnostic imaging , Uterine Artery/physiopathologyABSTRACT
OBJECTIVES: First, to investigate the additive value of second-trimester placental growth factor (PlGF) for the prediction of a small-for-gestational-age (SGA) neonate. Second, to examine second-trimester contingent screening strategies. METHODS: This was a prospective observational study in women with singleton pregnancy undergoing routine ultrasound examination at 19-24 weeks' gestation. We used the competing-risks model for prediction of SGA. The parameters for the prior model and the likelihoods for estimated fetal weight (EFW) and uterine artery pulsatility index (UtA-PI) were those presented in previous studies. A folded-plane regression model was fitted in the dataset of this study to describe the likelihood of PlGF. We compared the prediction of screening by maternal risk factors against the prediction provided by a combination of maternal risk factors, EFW, UtA-PI and PlGF. We also examined the additive value of PlGF in a policy that uses maternal risk factors, EFW and UtA-PI. RESULTS: The study population included 40 241 singleton pregnancies. Overall, the prediction of SGA improved with increasing degree of prematurity, with increasing severity of smallness and in the presence of coexisting pre-eclampsia. The combination of maternal risk factors, EFW, UtA-PI and PlGF improved significantly the prediction provided by maternal risk factors alone for all the examined cut-offs of birth weight and gestational age at delivery. Screening by a combination of maternal risk factors and serum PlGF improved the prediction of SGA when compared to screening by maternal risk factors alone. However, the incremental improvement in prediction was decreased when PlGF was added to screening by a combination of maternal risk factors, EFW and UtA-PI. If first-line screening for a SGA neonate with birth weight < 10th percentile delivered at < 37 weeks' gestation was by maternal risk factors and EFW, the same detection rate of 90%, at an overall false-positive rate (FPR) of 50%, as that achieved by screening with maternal risk factors, EFW, UtA-PI and PlGF in the whole population can be achieved by reserving measurements of UtA-PI and PlGF for only 80% of the population. Similarly, in screening for a SGA neonate with birth weight < 10th percentile delivered at < 30 weeks, the same detection rate of 90%, at an overall FPR of 14%, as that achieved by screening with maternal risk factors, EFW, UtA-PI and PlGF in the whole population can be achieved by reserving measurements of UtA-PI and PlGF for only 70% of the population. The additive value of PlGF in reducing the FPR to about 10% with a simultaneous detection rate of 90% for a SGA neonate with birth weight < 3rd percentile born < 30 weeks, is gained by measuring PlGF in only 50% of the population when first-line screening is by maternal factors, EFW and UtA-PI. CONCLUSIONS: The combination of maternal risk factors, EFW, UtA-PI and PlGF provides effective second-trimester prediction of SGA. Serum PlGF is useful for predicting a SGA neonate with birth weight < 3rd percentile born < 30 weeks after an inclusive assessment by maternal risk factors and biophysical markers. Similar detection rates and FPRs can be achieved by application of contingent screening strategies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Fetal Growth Retardation/diagnosis , Pregnancy Trimester, Second , Ultrasonography, Prenatal/methods , Adult , Female , Fetal Growth Retardation/diagnostic imaging , Humans , Placenta Growth Factor/blood , Pregnancy , Prenatal Diagnosis/methods , Prospective Studies , Uterine Artery/diagnostic imaging , Young AdultABSTRACT
OBJECTIVE: To examine the predictive performance of the relevant guideline by the Royal College of Obstetricians and Gynaecologists (RCOG) for neonates that are small for gestational age (SGA), and to compare the performance of the RCOG guideline with that of our competing risks model for SGA. DESIGN: Prospective observational study. SETTING: Obstetric ultrasound departments in two UK maternity hospitals. POPULATION: A total of 96 678 women with singleton pregnancies attending for routine ultrasound examination at 19-24 weeks of gestation. METHODS: Risks for SGA for different thresholds were computed, according to the competing risks model using maternal history, second-trimester estimated fetal weight, uterine artery pulsatility index and mean arterial pressure. The detection rates by the RCOG guideline scoring system and the competing risks model for SGA were compared, at the screen positive rate (SPR) derived from the RCOG guideline. MAIN OUTCOME MEASURES: Small for gestational age (SGA), <10th or <3rd percentile, for different gestational age thresholds. RESULTS: At an SPR of 22.5%, as defined by the RCOG guideline, the competing risks model predicted 56, 72 and 81% of cases of neonates that are SGA, with birthweights of <10th percentile, delivered at ≥37, <37 and <32 weeks of gestation, respectively, which were significantly higher than the respective figures of 36, 44 and 45% achieved by the application of the RCOG guideline. The respective figures for neonates that were SGA with birthweights of <3rd percentile were 66, 79, 85 and 41, 45, 44%. CONCLUSION: The detection rate for neonates that were SGA with the competing risk approach is almost double than that obtained with the RCOG guideline. TWEETABLE ABSTRACT: The competing risks approach for the prediction of SGA performs better than the existing RCOG guideline.
Subject(s)
Fetal Growth Retardation/diagnostic imaging , Guidelines as Topic , Infant, Small for Gestational Age , Ultrasonography, Doppler/methods , Ultrasonography, Prenatal/methods , Uterine Artery/diagnostic imaging , Adult , Arterial Pressure , Female , Fetal Growth Retardation/diagnosis , Fetal Weight , Gestational Age , Humans , Infant, Newborn , Predictive Value of Tests , Pregnancy , Pregnancy Trimester, Second , Prospective Studies , Pulsatile FlowABSTRACT
OBJECTIVE: To estimate the chorionic villus sampling (CVS)-related risk of fetal loss in twin pregnancy after adjustment for chorionicity, nuchal translucency thickness (NT), intertwin discordance in crown-rump length (CRL), maternal demographic characteristics and serum pregnancy-associated plasma protein-A (PAPP-A) and free ß-human chorionic gonadotropin (ß-hCG). METHODS: This was a multicenter study from eight fetal medicine units in which the leadership were trained at the Harris Birthright Research Centre for Fetal Medicine in London, UK, and in which the protocols for screening, invasive testing and pregnancy management are similar. Data were obtained prospectively from women with twin pregnancy undergoing routine ultrasound examination at 11-13 weeks' gestation. Multivariable logistic regression analysis with backward stepwise elimination was used to examine whether CVS provided a significant independent contribution to the prediction of risk of fetal loss after adjusting for maternal and pregnancy characteristics, including maternal age, racial origin and weight, method of conception, smoking status, parity, chorionicity, intertwin discordance in CRL, fetal NT ≥ 95th percentile and free ß-hCG and PAPP-A multiples of the median. Similarly, within the CVS group, multivariable logistic regression analysis was used to investigate the effect of the number of intrauterine needle insertions and size of the needle on the risk of fetal loss. RESULTS: The study population of 8581 twin pregnancies undergoing ultrasound examination at 11-13 weeks' gestation included 316 dichorionic and 129 monochorionic twins that had CVS. First, in twin pregnancies undergoing CVS, compared to those not undergoing CVS, there was a 2-fold increased risk of fetal loss at < 24 weeks' gestation and of loss at any stage in pregnancy. Second, the factors providing a significant independent contribution to the prediction of miscarriage or fetal loss in twin pregnancy were increased maternal weight, black racial origin, monochorionicity, and more so monoamnionicity, large intertwin discordance in CRL and increased fetal NT, and, in the case of fetal loss at any stage, there was also a contribution from assisted conception and low serum PAPP-A. Third, after adjustment for maternal and pregnancy characteristics, CVS did not provide a significant contribution to the risk of fetal loss. Fourth, in twin pregnancies that had CVS, there was no significant contribution to fetal loss from the number of intrauterine needle insertions or needle size. CONCLUSION: The 2-fold increased risk of fetal loss following CVS in twin pregnancy can, to a great extent, be explained by maternal and pregnancy characteristics rather than the invasive procedure itself. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Abortion, Spontaneous/etiology , Chorionic Villi Sampling/adverse effects , Pregnancy, Twin/statistics & numerical data , Prenatal Diagnosis/statistics & numerical data , Twins/statistics & numerical data , Abortion, Spontaneous/epidemiology , Adult , Chorion , Chorionic Gonadotropin, beta Subunit, Human/blood , Crown-Rump Length , Female , Gestational Age , Humans , Logistic Models , London/epidemiology , Nuchal Translucency Measurement , Pregnancy , Pregnancy Trimester, First/blood , Pregnancy, Twin/blood , Pregnancy-Associated Plasma Protein-A/analysis , Risk Factors , Ultrasonography, Prenatal/statistics & numerical dataABSTRACT
OBJECTIVE: To expand the limited knowledge on cell-free DNA (cfDNA) analysis of maternal blood for trisomies 21, 18 and 13 in twin pregnancy by updating the data from The Fetal Medicine Foundation (FMF) on prospective first-trimester screening and those identified in a systematic review of the literature. METHODS: The FMF data were derived from prospective screening for trisomies 21, 18 and 13 in twin pregnancies at 10 + 0 to 14 + 1 weeks' gestation using the Harmony® prenatal test. A search of MEDLINE, EMBASE, CENTRAL (The Cochrane Library), ClinicalTrials.gov and the International Clinical Trials Registry Platform (World Health Organization) was carried out to identify all peer-reviewed publications on clinical validation or implementation of maternal cfDNA testing for trisomies 21, 18 and 13 in twin pregnancy, irrespective of gestational age at testing, in which data on pregnancy outcome were provided for at least 85% of the study population. Meta-analysis was performed using the FMF data and data from the studies identified by the literature search. This review was registered in the PROSPERO international database for systematic reviews RESULTS: In the FMF study, cfDNA testing was carried out in 1442 twin pregnancies and a result was obtained, after first or second sampling, in 1367 (94.8%) cases. In 93.1% (1272/1367) of cases, there was prenatal or postnatal karyotyping or birth of phenotypically normal babies; 95 cases were excluded from further analysis either because the pregnancy ended in termination, miscarriage or stillbirth with no known karyotype (n = 56) or there was loss to follow-up (n = 39). In the 1272 pregnancies included in the study, there were 20 cases with trisomy 21, 10 with trisomy 18, two with trisomy 13 and 1240 without trisomy 21, 18 or 13. The cfDNA test classified correctly 19 (95.0%) of the 20 cases of trisomy 21, nine (90.0%) of the 10 cases of trisomy 18, one (50.0%) of the two cases of trisomy 13 and 1235 (99.6%) of the 1240 cases without any of the three trisomies. The literature search identified 12 relevant studies, excluding our papers because their data are included in the current study. In the combined populations of our study and the 12 studies identified by the literature search, there were 137 trisomy-21 and 7507 non-trisomy-21 twin pregnancies; the pooled weighted detection rate (DR) and false-positive rate (FPR) were 99.0% (95% CI, 92.0-99.9%) and 0.02% (95% CI, 0.001-0.43%), respectively. In the combined total of 50 cases of trisomy 18 and 6840 non-trisomy-18 pregnancies, the pooled weighted DR and FPR were 92.8% (95% CI, 77.6-98.0%) and 0.01% (95% CI, 0.00-0.44%), respectively. In the combined total of 11 cases of trisomy 13 and 6290 non-trisomy-13 pregnancies, the pooled weighted DR and FPR were 94.7% (95% CI, 9.14-99.97%) and 0.10% (95% CI, 0.03-0.39%), respectively. CONCLUSIONS: In twin pregnancy, the reported DR of trisomy 21 by cfDNA testing is high, but lower than that in singleton pregnancy, whereas the FPR appears to be equally low. The number of cases of trisomy 18 and more so trisomy 13 was too small for accurate assessment of the predictive performance of the cfDNA test. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Cell-Free Nucleic Acids/blood , Pregnancy, Twin , Prenatal Diagnosis , Trisomy/diagnosis , Cohort Studies , Female , Humans , Pregnancy , Pregnancy Trimester, FirstABSTRACT
OBJECTIVES: To derive accurate estimates of perinatal survival in pregnancies with and without a prenatal diagnosis of vasa previa based on a systematic review of the literature and meta-analysis. METHODS: A search of MEDLINE, EMBASE and The Cochrane Library was performed to review relevant citations reporting on the perinatal outcomes of pregnancies with vasa previa. We included prospective and retrospective cohort and population studies that provided data on pregnancies with a prenatal diagnosis of vasa previa or cases diagnosed at birth or following postnatal placental examination. Meta-analysis using a random-effects model was performed to derive weighted pooled estimates of perinatal survival (excluding stillbirths and neonatal deaths) and intact perinatal survival (additionally excluding hypoxic morbidity). Incidence rate difference (IRD) meta-analysis was used to estimate the significance of differences in pooled proportions between cases of vasa previa with and those without a prenatal diagnosis. Heterogeneity between studies was estimated using Cochran's Q and the I2 statistic. RESULTS: We included 21 studies reporting on the perinatal outcomes of 683 pregnancies with a prenatal diagnosis of vasa previa. There were three stillbirths (1.01% (95% CI, 0.40-1.87%)), five neonatal deaths (1.19% (95% CI, 0.52-2.12%)) and 675 surviving neonates, resulting in a pooled estimate for perinatal survival of 98.6% (95% CI, 97.6-99.3%). Based on seven studies that included cases of vasa previa with and without a prenatal diagnosis, the pooled perinatal survival in pregnancies without a prenatal diagnosis (61/118) was 72.1% (95% CI, 50.6-89.4%) vs 98.6% (95% CI, 96.7-99.7%) in cases with a prenatal diagnosis (224/226). Therefore, the risk of perinatal death was 25-fold higher when a diagnosis of vasa previa was not made antenatally, compared with when it was (odds ratio (OR), 25.39 (95% CI, 7.93-81.31); P < 0.0001). Similarly, the risk of hypoxic morbidity was increased 50-fold in cases with vasa previa without a prenatal diagnosis compared with those with a prenatal diagnosis (36/61 vs 5/224; OR, 50.09 (95% CI, 17.33-144.79)). The intact perinatal survival rate in cases of vasa previa without a prenatal diagnosis was significantly lower than in those with a prenatal diagnosis (28.1% (95% CI, 14.1-44.7%) vs 96.7% (95% CI, 93.6-98.8%)) (IRD, 73.4% (95% CI, 53.9-92.7%); Z = -7.4066, P < 0.001). CONCLUSIONS: Prenatal diagnosis of vasa previa is associated with a high rate of perinatal survival, whereas lack of an antenatal diagnosis significantly increases the risk of perinatal death and hypoxic morbidity. Further research should be undertaken to investigate strategies for incorporating prenatal screening for vasa previa into routine clinical practice. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Subject(s)
Pregnancy Outcome/epidemiology , Prenatal Diagnosis/statistics & numerical data , Vasa Previa/diagnosis , Vasa Previa/mortality , Female , Humans , Infant, Newborn , Perinatal Mortality , Pregnancy , Prospective Studies , Retrospective StudiesSubject(s)
Coronavirus Infections/prevention & control , Delivery of Health Care/methods , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Ultrasonography, Prenatal/methods , Appointments and Schedules , COVID-19 , Coronavirus Infections/diagnosis , Coronavirus Infections/transmission , Delivery of Health Care/organization & administration , Female , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Infectious Disease Transmission, Professional-to-Patient/prevention & control , Masks , Mass Screening , Obstetrics , Patient Isolation , Pneumonia, Viral/diagnosis , Pneumonia, Viral/transmission , Point-of-Care Testing , Pregnancy , Quarantine , Telemedicine , Triage/methodsABSTRACT
OBJECTIVES: To examine the performance of the routine 11-13-week scan in detecting fetal defects in twin pregnancies and to examine if, in pregnancies with a fetal defect, compared to those with normal fetuses, there is increased incidence of nuchal translucency thickness (NT) ≥ 95th and ≥ 99th percentiles or intertwin discordance in crown-rump length (CRL) ≥ 10% and ≥ 15%. METHODS: This was a retrospective analysis of prospectively collected data in twin pregnancies undergoing routine ultrasound examination for fetal anatomy, according to standardized protocols, at 11-13 weeks' gestation between 2002 and 2019. Pregnancies with known chromosomal abnormality were excluded. The final diagnosis of fetal defect was based on the results of postnatal examination in cases of live birth and on the findings of the last ultrasound examination in cases of pregnancy termination, miscarriage or stillbirth. The performance of the 11-13-week scan in the detection of fetal defects was determined. RESULTS: The study population of 6366 twin pregnancies with two live fetuses at 11-13 weeks' gestation included 4979 (78.2%) dichorionic (DC) and 1387 (21.8%) monochorionic (MC) twin pregnancies. The main findings were: first, the overall incidence of fetal defects was higher in MC than in DC twins (2.8% vs 1.3%); second, the proportion of defects diagnosed in the first trimester was higher in MC than in DC twins (52.6% vs 27.1%); third, the pattern of defects in relation to detectability at the 11-13-week scan (always detectable, sometimes detectable and never detectable) was similar to that reported previously in singleton pregnancies; fourth, always-detectable defects included acrania, alobar holoprosencephaly, encephalocele, pentalogy of Cantrell, exomphalos, body-stalk anomaly, twin reversed arterial perfusion sequence and conjoined twins; fifth, the incidence of fetal NT ≥ 95th percentile was higher in those with than in those without a defect (16.5% vs 4.5% in DC twins and 19.2% vs 5.9% in MC twins) and this was also true for NT ≥ 99th percentile (8.3% vs 1.0% in DC twins and 15.4% vs 2.0% in MC twins); and sixth, the incidence of CRL discordance ≥ 10% was higher in those with than in those without a defect (20.2% vs 7.9% in DC twins and 33.8% vs 9.3% in MC twins) and this was also true for CRL discordance ≥ 15% (10.1% vs 1.9% in DC twins and 28.2% vs 2.8% in MC twins). CONCLUSIONS: First, fetal defects are more common in MC than in DC twin pregnancies. Second, first-trimester detection of fetal defects in DC twin pregnancies is similar to that in singleton pregnancies. Third, first-trimester detectability of defects in MC twins is higher than in DC twins. Fourth, in twin pregnancies with a fetal defect, there is higher intertwin discordance in CRL and incidence of increased NT, but the predictive performance of screening by these markers is poor. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Diagnóstico de defectos del feto en embarazos de gemelos en el examen ecográfico de rutina de las 11-13 semanas OBJETIVOS: Examinar la eficacia del examen rutinario de 11-13 semanas para detectar defectos fetales en embarazos de gemelos y examinar si, en los embarazos con un defecto fetal, en comparación con los de fetos normales, hay una mayor incidencia del grosor de la translucencia nucal (TN) ≥ percentil 95o y ≥ percentil 99o o una discordancia entre gemelos en la longitud céfalo-caudal (LCC) ≥10% y ≥15%. MÉTODOS: Este estudio fue un análisis retrospectivo de datos recogidos prospectivamente de embarazos de gemelos sometidos a exámenes ecográficos de rutina entre 2002 y 2019 para determinar la anatomía del feto, según protocolos estándar a las 11-13 semanas de gestación. Se excluyeron los embarazos con anomalías cromosómicas conocidas. El diagnóstico final de la anomalía fetal se basó en los resultados del examen posnatal en los casos de nacimientos vivos y en los hallazgos del último examen ecográfico en los casos de interrupción del embarazo, aborto o éxitus fetal. Se determinó la eficacia de la exploración de las 11-13 semanas en la detección de anomalías fetales. RESULTADOS: La población de estudio fue de 6366 embarazos de gemelos con dos fetos vivos a las 11-13 semanas de gestación e incluyó 4979 (78,2%) embarazos bicoriales (BC) y 1387 (21,8%) monocoriales (MC). Los principales hallazgos fueron: primero, la prevalencia total de defectos fetales fue mayor en los gemelos MC que en los gemelos BC (2,8% vs. 1,3%); segundo, la proporción de defectos diagnosticados en el primer trimestre fue mayor en los gemelos MC que en los gemelos BC (52,6% vs. 27,1%); tercero, la pauta de defectos en relación con la detectabilidad en la exploración de 11-13 semanas (siempre detectable, a veces detectable y nunca detectable) fue similar a la reportada previamente para los embarazos con feto único; cuarto, entre los defectos siempre detectables estaban la acrania, la holoprosencefalia alobar, el encefalocele, la pentalogía de Cantrell, el onfalocele, la anomalía del pedículo embrionario, la secuencia de perfusión arterial inversa de los gemelos y los gemelos unidos; quinto, la frecuencia del percentil de la TN fetal ≥95o fue mayor en los que tenían un defecto que en los que no lo tenían (16,5% vs 4,5% en los gemelos BC y 19,2% vs 5,9% en los gemelos MC) y esto también fue cierto para el percentil de la TN ≥99o (8,3% vs 1,0% en gemelos BC y 15,4% vs 2,0% en gemelos MC); y sexto, la frecuencia de una discordancia de la LCC ≥10% fue mayor en los que tenían un defecto que en los que no lo tenían (20,2% vs 7,9% en los gemelos BC y 33,8% vs 9,3% en los gemelos MC) y esto también fue cierto para la discordancia de la LCC ≥15% (10,1% vs 1,9% en los gemelos BC y 28,2% vs 2,8% en los gemelos MC). CONCLUSIONES: Primero, los defectos fetales son más comunes en embarazos de gemelos MC que en los de gemelos BC. Segundo, la detección en el primer trimestre de defectos fetales en los embarazos de gemelos BC es similar a la de los embarazos con feto único. Tercero, la detectabilidad en el primer trimestre de los defectos en los gemelos MC es mayor que en los gemelos BC. Cuarto, en los embarazos de gemelos con un defecto fetal, hay mayor discordancia entre los gemelos en la LCC y prevalencia de una mayor TN, pero la eficacia predictiva del cribado mediante estos marcadores es escasa.
Subject(s)
Crown-Rump Length , Fetal Diseases/diagnostic imaging , Nuchal Translucency Measurement/statistics & numerical data , Ultrasonography, Prenatal/statistics & numerical data , Adult , Female , Gestational Age , Humans , Predictive Value of Tests , Pregnancy , Pregnancy Trimester, First , Pregnancy Trimester, Second , Pregnancy, Twin , Prospective Studies , Retrospective Studies , Twins, Dizygotic , Twins, Monozygotic , Ultrasonography, Prenatal/methodsABSTRACT
OBJECTIVES: Prenatal diagnosis of coarctation of the aorta (CoA) is associated with reduced mortality and morbidity, however, accurate prenatal prediction remains challenging. To date, studies have used retrospective measurements of the outflow tracts to evaluate their potential to predict CoA. Our primary objective was to evaluate prospectively acquired measurements of the outflow tracts in fetuses with prenatally suspected CoA. A secondary aim was to report the postnatal prevalence of bicuspid aortic valve in this cohort. METHODS: Pregnancies with suspicion of isolated CoA and with a minimum of 6 months' postnatal follow-up available were identified from the cardiac database of a tertiary fetal cardiology center in the UK, between January 2002 and December 2017. Measurement of the aortic valve, pulmonary valve, distal transverse aortic arch (DTAA) and arterial duct (AD) diameters were undertaken routinely in fetuses with suspected CoA during the study period. Z-scores were computed using published reference ranges based on > 7000 fetuses from our own unit. RESULTS: Of 149 pregnancies with prenatally suspected CoA included in the study, CoA was confirmed within 6 months after birth in 77/149 (51.7%) cases. DTAA diameter Z-score and the Z-score of second-trimester DTAA/AD diameter ratio were smaller in fetuses with postnatally confirmed CoA than those in false-positive cases (-2.8 vs -1.9; P = 0.039 and -3.13 vs -2.61; P = 0.005, respectively). Multiple regression analysis demonstrated that the Z-scores of DTAA and AD diameters were the only significant predictors of postnatal CoA (P = 0.001). Bicuspid aortic valve was identified in 30% of the false-positive cases. CONCLUSIONS: Measurement of DTAA and AD diameter Z-scores can be used to ascertain risk for postnatal CoA in a selected cohort. The high incidence of bicuspid aortic valve in false-positive cases merits further study with respect to both etiology and longer-term significance. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.